1. Field of the Invention
The present invention relates to a transport carriage system, and in particular to a system in which multiple transport carriages travel on a common track.
2. Description of the Related Art
In a known transport system, for example, two stacker cranes travel back and forth on a common track, and interference is avoided through communication between the cranes (JP 3791643B). With this technology, multiple cranes communicate their current position, velocity, target position, and the like to each other in order to travel and stop when necessary so as to avoid interference. Note that multiple stacker cranes travel along a common track in order to raise transport performance in an automated warehouse or the like. Also, in order to improve the level of cleanliness in an automated warehouse, the stacker cranes receive electricity from a common contactless power feeding apparatus.
In accordance with instruction from a host controller, a stacker crane travels to a destination in order to deliver and receive articles, for example. Upon receiving an instruction regarding a destination from the host controller, the stacker crane generates a velocity pattern for the range up to the destination using an on-board controller, and inputs the velocity pattern data to the servo system of a traveling motor. The servo system travels such that error between the input velocity pattern and the actual velocity is eliminated. Since multiple cranes travel on a common track, there are cases where, for example, the destination is changed in order to avoid interference or the like, or the target velocity is changed to conform to a leading stacker crane so as to follow it. This leads to the possibility of the crane or the transported articles being negatively influenced due to a sudden change in the instruction input to the servo system, or a sudden change in acceleration/deceleration.